A method of reference phase velocity selecting for bearing estimation with a horizontal line array in shallow water

Area of Science:

• Acoustics
• Oceanography
• Signal Processing

Background:

• Accurate direction-of-arrival (DOA) estimation is vital for underwater acoustic source localization.
• In shallow water, the choice of reference phase velocity significantly impacts DOA estimation accuracy with beamformed horizontal line arrays.
• Mismatched reference phase velocity leads to deviations in the estimated source bearing.

Purpose of the Study:

• To analyze the relationship between reference phase velocity and factors influencing DOA estimation.
• To develop an improved method for selecting reference phase velocity in shallow water environments.
• To enhance the accuracy of source bearing estimation using underwater horizontal line arrays.

Main Methods:

• Analysis of the intrinsic relationship between reference phase velocity, normal mode amplitude distribution, source bearing, and array aperture.
• Development of a multi-parameter weighted reference phase velocity selection method.
• Validation through numerical simulations and experimental data.

Main Results:

• A direct correlation was found between reference phase velocity and normal mode characteristics.
• The proposed multi-parameter weighted method demonstrated improved accuracy in source bearing estimation compared to traditional methods.
• Deviations in estimated bearing due to mismatched velocity were quantified.

Conclusions:

• The proposed method effectively improves source bearing estimation accuracy in shallow water environments.
• Accurate reference phase velocity selection is critical for reliable DOA estimation with horizontal line arrays.
• The findings are validated by both numerical simulations and experimental results.